© Dan Murphy, www.opost.com/dlm, via http://history-computer.com/Internet/Maturing/Tomlinson.html

Ray Tomlinson, who developed what we now know as email, has died at the age of 74. As well as the technology itself, he created the use of the @ sign in addresses.

Tomlinson worked at tech firm Bolt, Beranek and Newman and developed some key technologies for ARPANET, the military network that lay the groundwork for the Internet.

In 1971 he worked on a program called SNDMSG which was designed for people who used the same computer at different times (a common setup given the expense and size of computers) to leave messages for one another, like a virtual postbox.

Tomlinson tweaked SNDMSG by adding code from a network file transfer program named CPYNET, making it theoretically possible to transfer these messages between two different computers. He then achieved this after solving the logistical problem of distinguishing messages designed for a local recipient and a networked one.This he did by using the @ symbol, which he said simply showed the recipient was at another location rather then sited locally.

He went on to successfully test the system with a message between two computers (pictured) that, although sat next to one another, were only connected by ARPANET: “The test messages were entirely forgettable and I have, therefore, forgotten them. Most likely the first message was QWERTYUIOP or something similar. ”

Once he was happy the system worked, Tomlinson used it to send a message to his colleagues explaining how to send network messages, meaning “The first use of network email announced its own existence.”